Freshwater browning as a hidden threat - Transcriptomic responses in fish gills exposed to fulvic acid.

Human activities and climate change have significantly increased humic substances in freshwater ecosystems over the last few decades. This increase is particularly concerning during seasonal changes or after heavy rainfall, when concentrations can easily increase up to tenfold. This phenomenon, known as "browning," has unknown consequences for aquatic organisms.

Effects of Feed Supplementation With Fulvic Acid on the Systemic and Mucosal Protective Mechanisms of Juvenile Rainbow Trout (Oncorhynchus mykiss).

Rainbow trout (Oncorhynchus mykiss) is an important fish species raised in aquaculture, but it is susceptible to stress, infections diseases. The present study aimed to determine the effects of fulvic acid feed addition on the systemic and mucosal protective mechanisms of juvenile rainbow trout and to elucidate the underlying molecular mechanisms of changes in the gut. Rainbow trout (4.

Dietary fulvic acid improves immune, digestive and antioxidant parameters in juvenile white-leg shrimp (Litopenaeus vannamei) in a super-intensive system.

In the current study, the effects of dietary fulvic acid supplementation at levels of 0.5, 1 and 2% were examined in white-leg shrimp, Litopenaeus vannamei. A significant increase in the weight of the shrimp was observed in the group treated with 2% fulvic acid in comparison to the control group.

Fulvic acid modulates mucosal immunity in fish skin: Sustainable aquaculture solution or environmental risk factor?

This is the first study determining the effects of bath exposure to fulvic acid, a humic substance, on the skin mucosal immunity of rainbow trout (Oncorhynchus mykiss). Humic substances have recently been gaining attention for their increasing concentrations in aquatic ecosystems and their use as supplements in sustainable aquaculture. This study demonstrated that water exposure to fulvic acid at concentrations of 5 mg C/L and 50 mg C/L increased lysozyme and alkaline phosphatase activities in the mucus by approximately 2-fold and 2.